The Synergistic Effects of Low-Concentration Acidic Electrolyzed Water and Ultrasound on the Storage Quality of Fresh-Sliced Button Mushrooms

The objective of this study was to determine the effects of low-concentration acidic electrolyzed water (LcEW) combined with ultrasound (US) on fresh-sliced button mushrooms (Agaricus bisporus), by evaluating the enzymatic browning, physio-biochemical changes, and microbial loads. The sliced button mushrooms were divided randomly into three groups (control, LcEW, and LcEW+US) and treated separately with tap water, LcEW, and LcEW+US for 3 min, and afterwards, they were stored at 5 °C for 8 days. The results indicated that LcEW delayed surface browning and maintained the flesh firmness of fresh-cut mushrooms compared with the control, and ultrasound enhanced these effects. Moreover, LcEW+US slowed down the electrolyte leakage (EL) rate and malondialdehyde (MDA) content, which were 5.29% and 0.5227 μmol/fresh weight less than those in control at day 8, respectively. The combined treatment of LcEW and US also significantly inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD) and controlled the counts of total bacteria (TBC) and yeast and mold counts (Y&M). Meanwhile, LcEW+US maintained a high level of total soluble protein and total phenolic contents, which were 1.49 and 1.24 times higher than those in control at the end of the storage time, respectively, and the combined treatment was more effective than LcEW treatment alone. These results demonstrated that the combination of LcEW and US could be an effective pretreatment technology in maintaining the product quality and prolonging the shelf life of fresh-sliced button mushrooms.